FINALS POINTERS Flashcards
Where metabolic exchange between the blood and the tissue takes place
CAPILLARIES
Lined by a single continuous layer of endothelial cells supported by a basement membrane
CAPILLARIES
Lumen is large enough that only one leukocyte or red cell can pass
CAPILLARIES
Characterized by openings called JUNCTIONS where nutrients and excretory materials pass
CAPILLARIES
RBCs and platelets DO NOT leave the vessel lumen
CAPILLARIES
CAPILLARIES The blood vascular system has a continuous lining that consists of a single layer of
ENDOTHELIAL CELLS
are simple endothelial tubes that connect the arterial and venous sides of the circulation
Capillaries
are surrounded by a thin sheath of delicate collagenous and reticular fibers and accompanied by occasional perivascular cells (PERICYTES)
Capillaries
CONTINUOUS CAPILLARY
Muscles, Lung, CNS, and skin
FENESTRATED CAPILLARY
Intestinal mucosa,
endocrine glands,
renal glomerulus, and
pancreas
SINUSOIDAL
CAPILLARY
Liver,
bone marrow, and
spleen
capillaries are vessels intermediate between the arteries and capillaries and veins and capillaries
ARTERIAL (pre-) and VENOUS (post-)
have wider lumens and contain scattered smooth muscles
ARTERIAL CAPILLARIES (Metarterioles)
Oriented LONGITUDINALLY unlike that of arterioles (which are transversely oriented)
ARTERIAL CAPILLARIES
Some ARTERIAL CAPILLARIES posses __ that exists in sites where capillaries arise from metarterioles
PRECAPILLARY SPHINCTERS
Characterized by more pericytes than the capillary networks
VENOUS CAPILLARIES (Postcapillary venules)
ARTERIES
TUNICA INTIMA (or INTERNA)
Layers:
- Inner endothelial lining
- Subendothelial layer (fibroelastic tissues)
- Internal elastic membrane
contains mainly circularly arranged smooth muscles with varying amounts of elastic and collagenous fibers
TUNICA MEDIA –
parallel lined connective tissue
Some contains a definite External elastic membrane
TUNICA EXTERNA (or ADVENTITIA) –
SPECIALIZED ARTERIES
INTRACRANIAL ARTERIES
LUNG
UMBILICAL ARTERIES
PENILE ARTERIES
thin walled and well developed internal elastic membrane
INTRACRANIAL ARTERIES
Reduction in elastic tissues and muscle (hence are thin)
LUNG:
posses a media composed of two, thick, muscular layer (inner longitudinal and outer circular) and lacks an internal elastic membrane
UMBILICAL ARTERIES :
intima is greatly thick and contains many longitudinal muscles
PENILE ARTERIES:
Accomodates a large volume of blood
Lumen is larger compared to capillaries
Classification
VEINS
Venules
Small to medium sized veins
Large veins
Some cardiac muscles extend a distance to the adventitia at the entrance to the heart
VENA CAVA and PULMONARY ARTERIES
GRAVID UTERUS,
LIMBS,
UMBILICAL VEIN,
MESENTERIC VEINS
Thick media
CEREBRAL and MENINGEAL VEINS,
DURAL SINUSES,
VEINS OF THE RETINA,
BONES,
PENILE ERECTILE
TISSUE and
PLACENTA
no tunica media
Seen in many small and medium sized veins
Are semilunar folds or pockets produced by local infolding of the INTIMA
VENOUS VALVES
Sites where arteries are directly connected to veins without any intervening capillary
ARTERIOVENOUS ANASTOMOSES
– convoluted outline surrounded by a CT sheath
GLOMUS
Seen in arteries and veins that are >1mm in diameter
Small nutrient blood vessels
VASA VASORUM
Intrinsic Pathway
Kininogen Kallikrein 12 11 9 8a 10 Prothrombin II Fibrinogen II
Extrinsic Pathway
7 Tissue factor 10 5a Thrombin IIa Fibrin Ia 13a
